Method for removing resist layer, and method of manufacturing semiconductor

ABSTRACT

A method for removing a resist layer including the following steps is provided. A patterned resist layer on a material layer is formed. A stripping solution is applied to the patterned resist layer to dissolve the patterned resist layer without dissolving the material layer, wherein the stripping solution comprises a non-dimethyl sulfoxide solvent and an alkaline compound, the non-dimethyl sulfoxide solvent comprises an aprotic solvent and a protic solvent.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of and claims thepriority benefit of a prior application Ser. No. 17/035,763, filed onSep. 29, 2020, now allowed. The entirety of the above-mentioned patentapplication is hereby incorporated by reference herein and made a partof this specification.

BACKGROUND

With the growing of semiconductor technologies, more functions need tobe integrated into semiconductor dies. Accordingly, the semiconductordies need to have increasingly greater numbers of I/O pads packed intosmaller areas, and the density of the I/O pads rises quickly over time.As a result, the packaging of the semiconductor dies becomes moredifficult, which adversely affects the yield of the packaging.Currently, integrated fan-out packages are becoming increasingly popularbecause the I/O pads on a die can be redistributed to a greater areathan the die, and hence the number of I/O pads packed on the surfaces ofthe dies can be increased. Another advantageous feature of thispackaging technology is that “known-good-dies” are packaged, anddefective dies are discarded, and hence cost and effort are not wastedon the defective dies.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1A to FIG. 1L are schematic cross-sectional views of various stagesin a method of manufacturing a package structure in accordance with someembodiments of the disclosure.

FIG. 2A is a schematic top view illustrating a portion of the structurein the stage of FIG. 1E in accordance with some embodiments of thedisclosure.

FIG. 2B is a schematic top view illustrating a portion of the structurein the stage of FIG. 1F in accordance with some embodiments of thedisclosure.

FIG. 3A to FIG. 3E are schematic cross-sectional views of various stepsin a stripping process for the patterned resist layer in FIG. 1D inaccordance with some embodiments of the disclosure.

FIG. 4 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure.

FIG. 5 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure.

FIG. 6 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure.

FIG. 7 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure.

FIG. 8 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure.

FIG. 9 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure.

FIG. 10 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure.

FIG. 11 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

In addition, terms, such as “first,” “second,” “third,” “fourth,” andthe like, may be used herein for ease of description to describe similaror different element(s) or feature(s) as illustrated in the figures, andmay be used interchangeably depending on the order of the presence orthe contexts of the description.

Other features and processes may also be included. For example, testingstructures may be included to aid in the verification testing of the 3Dpackaging or 3DIC devices. The testing structures may include, forexample, test pads formed in a redistribution layer or on a substratethat allows the testing of the 3D packaging or 3DIC, the use of probesand/or probe cards, and the like. The verification testing may beperformed on intermediate structures as well as the final structure.Additionally, the structures and methods disclosed herein may be used inconjunction with testing methodologies that incorporate intermediateverification of known good dies to increase the yield and decreasecosts.

FIG. 1A to FIG. 1L are schematic cross-sectional views of various stagesin a method of manufacturing a package structure in accordance with someembodiments of the disclosure.

Referring to FIG. 1A, a carrier C having a de-bonding layer DB and abuffer layer BL formed thereon is provided. In some embodiments, thecarrier C may be a glass carrier or any suitable carrier for carrying asemiconductor wafer or a reconstituted wafer for the manufacturingmethod of the package structure. In some embodiments, the carrier C mayhave a round top-view shape, and may have a size of a silicon wafer.

In some embodiments, the de-bonding layer DB is in physical contact withthe illustrated top surface of the carrier C, and may be formed by asuitable fabrication technique such as coating, lamination, ordeposition. In some embodiments, the material of the de-bonding layer DBmay be any material suitable for bonding and de-bonding the carrier Cfrom the above layer(s) or any wafer(s) disposed thereon. In someembodiments, the de-bonding layer DB may include a dielectric materiallayer made of a dielectric material including any suitable polymer-baseddielectric material (such as benzocyclobutene (BCB), polybenzoxazole(PBO)). In an alternative embodiment, the de-bonding layer DB mayinclude a dielectric material layer made of an epoxy-basedthermal-release material, which loses its adhesive property when heated,such as a light-to-heat-conversion (LTHC) release coating film. In afurther alternative embodiment, the de-bonding layer DB may include adielectric material layer made of an ultra-violet (UV) glue, which losesits adhesive property when exposed to UV lights. In certain embodiments,the de-bonding layer DB may be dispensed as a liquid and cured, or maybe a laminate film laminated onto the carrier C, or may be the like. Insome embodiments, the illustrated top surface of the de-bonding layerDB, which is opposite to the illustrated bottom surface contacting thecarrier C, may be levelled and may have a high degree of planarity, butthe disclosure is not limited thereto. In certain embodiments, thede-bonding layer DB is, for example, a LTHC release layer with goodchemical resistance, and such layer enables room temperature de-bondingfrom the carrier C by applying laser irradiation, however the disclosureis not limited thereto.

In some embodiments, the buffer layer BL is in physical contact with theillustrated top surface of the de-bonding layer DB, and the de-bondinglayer DB is located between the carrier C and the buffer layer BL. Insome embodiments, the buffer layer BL may be formed by a suitablefabrication technique such as coating, lamination, or deposition. Insome embodiments, the buffer layer BL is, for example, polymer such aspolyimide, BCB, PBO, or the like. In some alternative embodiments, thebuffer layer BL may include non-organic dielectric materials such assilicon oxide, silicon nitride, silicon carbide, silicon oxynitride, orthe like. It should be noted that the materials of the de-bonding layerDB, the carrier C and the buffer layer BL are merely for illustration,and the disclosure is not limited thereto. The illustrated top surfaceof the buffer layer BL, which is opposite to the illustrated bottomsurface contacting the de-bonding layer DB, may be levelled and may havea high degree of planarity. However, the disclosure is not limitedthereto; in other embodiments, the buffer layer BL may be omitted.

Referring to FIG. 1B, a seed layer SL is conformally formed on thede-bonding layer DB. In some embodiments, the seed layer SL is inphysical contact with the illustrated top surface of the de-bondinglayer DB. As shown in FIG. 1B, the seed layer SL is a single layer, butthe disclosure is not limited thereto. In some alternative embodiments,the seed layer SL may be a composite layer formed by differentmaterials. In some embodiments, the material of the seed layer SL mayinclude copper, copper alloys, titanium, titanium nitride, tantalum,tantalum nitride, a combination thereof, or other suitable materials. Incertain embodiments, the seed layer SL includes a titanium/coppercomposite layer. In some embodiments, the thickness of the seed layer SLmay range from about 10 nm to about 1000 nm. In some embodiments, theseed layer SL is formed by a suitable fabrication technique such assputtering, or physical vapor deposition (PVD).

Continued on FIG. 1B, a resist layer PR is formed on the seed layer SL.As shown in FIG. 1B, the resist layer PR is formed on the seed layer SLas a blanket layer to completely cover the seed layer SL. In someembodiments, the resist layer PR may be formed of a dry film photoresistlayer, which is laminated on the seed layer SL. In some alternativeembodiments, the resist layer PR may be formed of a liquid photoresistlayer, which is coated on the seed layer SL. In some embodiments, thematerial of the resist layer PR, for example, includes a positive resistmaterial or a negative resist material. In some embodiments, thematerial of the resist layer PR may include an ester group-containingresist material. In some embodiments, the resist layer PR is suitablefor a subsequent patterning process such as a photolithography processwith a mask (for instance, an extreme ultraviolet (EUV) lithography) ora mask-less photolithography process (for instance, an electron-beam(e-beam) writing or an ion-beam writing). In the disclosure, the resistlayer PR may be referred to as a photoresist layer.

Referring to FIG. 1C, the resist layer PR is patterned to form apatterned resist layer PR′ with a plurality of openings O formedtherein. As shown in FIG. 1C, portions of the seed layer SL are exposedby the openings O of the patterned resist layer PR′, respectively. Thenumber of the openings O may correspond to the number of later-formedconductive structure(s) (e.g. the metal patterns 102 depicted in FIG.1D), and thus the number of the openings O is not limited by theillustration presented in FIG. 1C. In other words, the patterned resistlayer PR′ may be referred to as a patterned mask layer for thelater-formed conductive structure(s). In some embodiments, as mentionedabove, the resist layer PR may be patterned through a photolithographyprocess with a mask, which may include the steps of providing aphotomask over the resist layer PR; globally irradiating the resistlayer PR with an electromagnetic radiation through the photomask toallow part of the resist layer PR to be exposed portions to theelectromagnetic radiation and rest of the resist layer PR to beunexposed portions to the electromagnetic radiation; removing thephotomask; and removing either the exposed portions or the unexposedportions of the resist layer PR through a developer to form thepatterned resist layer PR′ with the openings O. In some embodiments,each opening O is formed to have a round top-view shape. However, thedisclosure is not limited thereto. In some alternative embodiments, eachopening O may exhibit a polygonal shape or other suitable shapes fromthe top view. As shown in FIG. 1C, the sidewall of each opening O1defined by the patterned resist layer PR′ is in a vertical profile, butthe disclosure is not limited thereto. In some alternative embodiments,a reentrant profile with an undercut may be observed in a lower sidewallcorresponding to each opening O defined by the patterned resist layerPR′.

Referring to FIG. 1D, metal patterns 102 are formed on the seed layer SLand in the openings O. In some embodiments, the material of the metalpatterns 102 may include copper, aluminum, titanium, nickel, tungsten,and/or alloys thereof. In some embodiments, the metal patterns 102 maybe formed through electro-plating, electroless-plating, immersionplating, or the like. As shown in FIG. 1D, the illustrated top surfacesof the metal patterns 102 are lower than the illustrated top surface ofthe patterned resist layer PR′, so that the shapes of the metal patterns102 are confined by the openings O. That is to say, the contour of eachof the metal patterns 102 is substantially identical to the contour ofthe corresponding opening O. In other words, the top-view shape of eachof the metal patterns 102 is substantially identical to the top-viewshape of the corresponding opening O. Accordingly, in some embodiments,each metal pattern 102 is formed to have a round top-view shape.However, the disclosure is not limited thereto. In some alternativeembodiments, each metal pattern 102 may exhibit a polygonal shape orother suitable shapes from the top view. Moreover, as shown in FIG. 1D,due to the vertical sidewall of each opening O, the metal patterns 102have vertical side surfaces. However, the disclosure is not limitedthereto. In some alternative embodiments, due to a reentrant profilewith an undercut formed in a lower sidewall of each opening O, the metalpatterns 102 may not have vertical side surfaces.

In some embodiments, in a direction Z parallel to a normal direction ofthe carrier C, a height H₁ of each metal pattern 102 ranges betweenabout 15 μm and about 360 μm. In some embodiments, in a direction Xperpendicular the direction Z, a width W₁ of each metal pattern 102ranges between about 5 μm and about 120 μm. In the case that each metalpattern 102 has a round top-view shape (as shown in FIG. 2A), then thewidth W₁ may be the diameter. In the case that each metal pattern 102has a polygonal shape from the top view, then the width W₁ may be themaximum dimension. In some embodiments, an aspect ratio (i.e., a ratioof the height H₁ to the width W₁) of each metal pattern 102 is more thanabout 3, i.e., the metal patterns 102 are formed to have high aspectratio. In certain embodiments, the aspect ratio of each metal pattern102 is in a range from more than about 3 to about 15. As mentionedabove, the metal patterns 102 are formed in and confined by the openingsO of the patterned resist layer PR′, thereby in the case that an aspectratio (i.e., a ratio of the height H₁ to the width W₁) of each metalpattern 102 is more than about 3, an aspect ratio of each opening O mustbe more than about 3. In some embodiments, a pitch P₁ of two adjacentmetal patterns 102 ranges between about 6 μm and about 360 μm. Incertain embodiments, the pitch P₁ of two adjacent metal patterns 102ranges between about 30 μm and about 120 μm, i.e., the metal patterns102 can be formed to have high distribution density.

Referring to FIG. 1E, after the metal patterns 102 are formed, astripping process is performed to the patterned resist layer PR′ toremove the patterned resist layer PR′. In detail, during the strippingprocess, the patterned resist layer PR′ is removed to expose the seedlayer SL not covered by the metal patterns 102. That is to say, duringthe stripping process, the patterned resist layer PR′ is removed, whilethe underlying seed layer SL and the metal patterns 102 are remained. Inother words, after the stripping process, the metal patterns 102 areremained on the seed layer SL. In some embodiments, the metal patterns102 remained on the seed layer SL are in an array, as shown in FIG. 2Awhich is a schematic top view illustrating a portion of the structure inthe stage of FIG. 1E in accordance with some embodiments of thedisclosure. In the subsequent process, the metal patterns 102 are usedas a mask for partially removing the seed layer SL to render conductivethrough vias 100 (as shown in FIG. 1F). In view of this, referring toFIG. 2A and FIG. 1E, the structure obtained after the stripping processmay have a through-via-sparse region B and through-via-dense regions Asurrounded by the through-via-sparse region B. In detail, as shown inFIG. 2A, compared with the density of the metal patterns 102 in thethrough-via-sparse region B, the density of the metal patterns 102 inthe through-via-dense region A is relatively high. Further, in FIG. 2A,there is no metal pattern 102 in the through-via-sparse region B, butthe disclosure is not limited thereto. In some alternative embodiments,the metal patterns 102 may be in the through-via-sparse region B, whilethe density of the metal patterns 102 in the through-via-sparse region Bis quite low. It should be noted that the number of thethrough-via-dense regions A, and the arrangement of thethrough-via-sparse region B and the through-via-dense regions A shown inFIG. 2A are merely for illustration, and the disclosure is not limitedthereto.

During the conventional stripping process, if the metal patterns areformed to have high aspect ratio, the metal patterns at the boundary ofthe through-via-dense region tilt or collapse toward the neighboringthrough-via-sparse region, which results in failure of the resultingpackage structure. Referring to FIG. 2A and FIG. 1E, after the patternedresist layer PR′ is removed, the metal patterns 102 in thethrough-via-dense regions A remain substantially intact without tilting,falling or collapsing. That is to say, the metal patterns 102 in thethrough-via-dense regions A can be formed to have high aspect ratiowithout risking tilt or collapse of the metal patterns 102 at theboundary of the through-via-dense region A. The descriptions withrespect to the stripping process performed to the patterned resist layerPR′ will be discussed in greater detail below in conjunction with FIGS.3A-3E.

Referring to FIGS. 1D-1E and FIGS. 3A-3E, the stripping process isperformed to the patterned resist layer PR′ to dissolve the patternedresist layer PR′ without dissolving the seed layer SL and the metalpatterns 102. In detail, during the stripping process performed to thepatterned resist layer PR′, a stripping solution is applied to thepatterned resist layer PR′ to break the patterned resist layer PR′ intopieces and dissolve the pieces in the stripping solution. In someembodiments, the stripping solution may be applied by immersion or othersuitable methods.

In some embodiments, the stripping solution includes a non-dimethylsulfoxide solvent and an alkaline compound, and the non-dimethylsulfoxide solvent includes an aprotic solvent and a protic solvent. Thatis to say, the stripping solution used to dissolve the patterned resistlayer PR′ does not contain dimethyl sulfoxide solvent. In other words,the aprotic solvent does not include dimethyl sulfoxide. In someembodiments, the aprotic solvent may include N-methylpyrrolidone (NMP),tetrahydrofuran (THF), dimethylformamide (DMF), acetonitrile (MeCN) ordichloromethance (DCM), but not limited thereto. In some embodiments,the protic solvent is, for example, an alkanolamine solvent. Thealkanolamine solvent may include ethanol amine (MEA), methyl ethanolamine, 2-(2-aminoethylamino)ethanol, or diethanolamine, but not limitedthereto. As shown in FIG. 3A to FIG. 3B, the patterned resist layer PR′is less likely to swell up because the non-dimethyl sulfoxide solvent isused. In certain embodiments, the swelling percentage by volume of thepatterned resist layer PR′ during the stripping process is approaching0%. Large scale of swelling by volume may lead to high stress toward themetal patterns 102 and then may cause the metal patterns 102 to tilt,fall or collapse, therefore by using the non-dimethyl sulfoxide solvent,the stripping solution of the disclosure may minimize the fail ratio(e.g., tilt/collapse percentage) of the metal patterns 102. In someembodiments, the alkaline compound is, for example, a strong alkalinecompound. The strong alkaline compound may include tetra-methyl ammoniumhydroxide (TMAH), potassium hydroxide (KOH), sodium hydroxide (NaOH) ora combination thereof. In certain embodiments, the alkaline compoundincludes a mixture of TMAH and KOH. In detail, the alkaline compound maypermeate into the patterned resist layer PR′ while the non-dimethylsulfoxide solvent permeates into the patterned resist layer PR′, andthen the alkaline compound may react with the crosslinked structure ofthe patterned resist layer PR′ through the reaction to break thecrosslinked structure (i.e., to decompose the patterned resist layerPR′). Moreover, the protic solvent has a protic character, so that theprotic solvent may accelerate the dissolve rate of the decomposedpatterned resist layer PR′ into the non-dimethyl sulfoxide solvent.

As mentioned above, when the stripping solution includes the alkalinecompound and the non-dimethyl sulfoxide solvent containing the aproticsolvent and the protic solvent, the tilt/collapse percentage of themetal patterns 102 may be minimized, and the dissolve rate of thedecomposed patterned resist layer PR′ into the non-dimethyl sulfoxidesolvent may be increased. As such, referring to FIG. 3B to FIG. 3D, byusing the said stripping solution, the patterned resist layer PR′ can bebroke into pieces layer-by-layer from top to bottom, and the said piecescan be dissolved into the stripping solution. As a result, referring toFIG. 3D to FIG. 3E, there is little or no pulling force applied on themetal patterns 102 when some pieces peeling off from the metal patterns102. That is to say, by using the said stripping solution, the brokenpieces of the patterned resist layer PR′ are small enough not to causethe metal patterns 102 to tilt or collapse. In other words, while themetal patterns 102 have a high aspect ratio of more than about 3, byapplying the stripping solution including the alkaline compound and thenon-dimethyl sulfoxide solvent containing the aprotic solvent and theprotic solvent to the patterned resist layer PR′ in the strippingprocess, the metal patterns 102 in the through-via-dense regions A canremain substantially intact without tilting or collapsing, while thepatterned resist layer PR′ is removed by the stripping solution.Therefore, the performance and the quality of the subsequently formedpackage structure 10 may be ensured. Further, as shown in FIG. 3E,during the stripping process with the said stripping solution, thepatterned resist layer PR′ above the seed layer SL can be sufficientlyremoved without the presence of residue. That is to say, while the metalpatterns 102 are arranged to have high distribution density (e.g., thepitch P₁ of two adjacent metal patterns 102 ranges between about 30 μmand about 120 μm), the stripping solution including the alkalinecompound and the non-dimethyl sulfoxide solvent containing the aproticsolvent and the protic solvent used to remove the patterned resist layerPR′ still has good wetting ability. Accordingly, the performance and thequality of the subsequently formed package structure 10 may be ensured.

In some embodiments, based on a total weight of the stripping solution,an amount of the aprotic solvent is about 20 wt % to about 70 wt %, anamount of the protic solvent is about 20 wt % to about 70 wt %, and anamount of the alkaline compound is about 0.5 wt % to about 5.5 wt %. Incertain embodiments, in the case where the alkaline compound includesKOH, based on a total weight of the stripping solution, an amount of KOHis about 0.5 wt % to about 2.5 wt %. In certain embodiments, in the casewhere the alkaline compound includes TMAH, based on a total weight ofthe stripping solution, an amount of TMAH is about 0.5 wt % to about 3wt %. In certain embodiments, in the case where the aprotic solvent isused in an amount of about 20 wt % to about 70 wt %, the protic solventis used in an amount of about 20 wt % to about 70 wt % and the alkalinecompound is used in an amount of about 0.5 wt % to about 5.5 wt %, thenthe fail ratio (e.g., tilt/collapse percentage) of the metal patterns102 during the stripping process can be improved by about 35%. In someembodiments, a ratio of an amount of the aprotic solvent to an amount ofthe protic solvent ranges from about 1:3.5 to about 3.5:1. Specifically,in case where the aprotic solvent and the protic solvent are used in thedesignated ratio, then the fail ratio (e.g., tilt/collapse percentage)of the metal patterns 102 during the stripping process can be improvedby about 35%. In certain embodiments, a ratio of an amount of theaprotic solvent to an amount of the protic solvent may be 1:1. In someembodiments, the process time of the stripping process ranges from about1 minute to about 180 minutes. In some embodiments, the processtemperature of the stripping process ranges from about 25° C. to about100° C. Specifically, in case where the process time and the processtemperature of the stripping process fall within the above designatedrange, then the fail ratio (e.g., tilt/collapse percentage) of the metalpatterns 102 during the stripping process can be improved by about 35%.

Referring back to FIG. 1E and FIG. 1F, after the removal of thepatterned resist layer PR′, the portion of the seed layer SL not coveredby the metal patterns 102 is removed to form seed layer patterns 104between the buffer layer BL and the metal patterns 102. That is to say,the metal patterns 102 are serve as a mask for partially removing theseed layer SL. In other words, the seed layer patterns 104 areoriginated from the portion of the seed layer SL covered by the metalpatterns 102. In some embodiments, the seed layer SL is partiallyremoved through an etching process, such as an anisotropic etchingprocess or an isotropic etching process.

As mentioned above, during the stripping process, the patterned resistlayer PR′ can be sufficiently removed without the presence of residuewhile the metal patterns 102 can remain substantially intact withouttilting or collapsing by using the stripping solution including thealkaline compound and the non-dimethyl sulfoxide solvent containing theaprotic solvent and the protic solvent. In view of this, the contour ofthe seed layer patterns 104 formed after the removal of the patternedresist layer PR′ and by using the metal patterns 102 as an etching maskis substantially identical to the contour of the metal patterns 102, asshown in FIG. 1F. That is to say, the edge of each of the seed layerpatterns 104 is substantially flushed with the edge of the correspondingoverlying metal pattern 102. Since the contour of the seed layerpatterns 104 are identical to the contour of the metal patterns 102, theelectrical leakage problem caused by mismatch in shapes of the seedlayer pattern and metal patterns may be effectively eliminated, therebyensuring the performance and the quality of the subsequently formedpackage structure 10. In some embodiments, in the case where each metalpattern 102 has a round top-view shape, each seed layer pattern 104 isformed to have a round top-view shape. However, the disclosure is notlimited thereto. In some alternative embodiments, each seed layerpattern 104 may exhibit a polygonal shape or other suitable shapes fromthe top view.

In some embodiments, the seed layer patterns 104 and the metal patterns102 are collectively referred to as conductive through vias 100. Asillustrated in FIG. 1F, the conductive through vias 100 are disposed onthe buffer layer BL. As mentioned above, after the removal of thepatterned resist layer PR′ by applying the stripping solution includingthe alkaline compound and the non-dimethyl sulfoxide solvent containingthe aprotic solvent and the protic solvent to the patterned resist layerPR′, the metal patterns 102 can remain substantially intact withouttilting or collapsing, thereby the conductive through vias 100 formed byusing the metal patterns 102 as a mask can be formed to substantiallystand vertically on the buffer layer BL. That is to say, the conductivethrough vias 100 may protrude from the buffer layer BL substantiallyalong the direction Z. In other words, an extending direction which theconductive through via 100 along with and the direction Z may has anangular offset of less than 1°. Accordingly, the manufacturing yield ofthe conductive through vias 100 is significantly improved. In someembodiments, more than or equal to 95% of the conductive through vias100 have no angular offset relative to the direction Z, and less than orequal to 5% of the conductive through vias 100 have the angular offsetfrom the direction Z of less than 1°. In some alternative embodiments,almost all of the conductive through vias 100 have no angular offsetrelative to the direction Z.

In some embodiments, since the metal patterns 102 are formed in an array(as shown in FIG. 2A), the conductive through vias 100 of which themetal patterns 102 are parts are formed in an array, as shown in FIG. 2Bwhich is a schematic top view illustrating a portion of the structure inthe stage of FIG. 1F in accordance with some embodiments of thedisclosure. In some embodiments, in the direction Z, a height He of eachconductive through via 100 ranges between about 15 μm and about 360 μm.In some embodiments, in the direction X perpendicular the direction Z, awidth We of each conductive through via 100 ranges between about 5 μmand about 120 μm. In the case that the each conductive through via 100has a round top-view shape (as shown in FIG. 2B), then the width We maybe the diameter. In the case that each conductive through via 100 has apolygonal shape from the top view, then the width We may be the maximumdimension.

In some embodiments, an aspect ratio (i.e., a ratio of the height He tothe width Wc) of each conductive through via 100 is more than about 3,i.e., the conductive through vias 100 are formed to have high aspectratio. That is to say, by applying the stripping solution including thealkaline compound and the non-dimethyl sulfoxide solvent containing theaprotic solvent and the protic solvent in the stripping process torender the metal patterns 102 having high aspect ratio without tiltingor collapsing, the conductive through vias 100 having high aspect ratiocan be formed accordingly. In certain embodiments, the aspect ratio ofeach conductive through via 100 is in a range from more than about 3 toabout 15. Moreover, in some embodiments, a pitch Pc of two adjacentconductive through vias 100 ranges between about 6 μm and about 360 μm.In certain embodiments, the pitch Pc of two adjacent conductive throughvias 100 ranges between about 30 μm and about 120 μm, i.e., theconductive through vias 100 can be formed to have high distributiondensity. As mentioned above, since the stripping solution including thealkaline compound and the non-dimethyl sulfoxide solvent containing theaprotic solvent and the protic solvent used to remove the patternedresist layer PR′ has good wetting ability even while the metal patterns102 are arranged to have high distribution density, the conductivethrough vias 100 having high distribution density and having the contouridentical to the contour of the metal patterns 102 can be formedaccordingly. Therefore, the performance and the quality of thesubsequently formed package structure 10 may be ensured.

Referring to FIG. 1G, at least one die 110 may be picked and placed ontothe buffer layer BL. The die 110, for example, includes a semiconductorsubstrate 111, a plurality of conductive pads 112, a passivation layer113, a post-passivation layer 114, a plurality of conductive pillars115, and a protection layer 116. In detail, the die 110 is placed on thebuffer layer BL in a way that the semiconductor substrate 111 of the die110 is attached (or adhered) to the buffer layer BL. In someembodiments, the die 110 is attached (or adhered) to the buffer layer BLthrough a bonding film D. In some embodiments, the bonding film D may bean adhesive film, such as a die attach film (DAF). In some alternativeembodiments, the bonding film D may be any materials used for fusionbonding. For example, the bonding film D may be an oxide-based film(e.g., silicon oxide film) used for oxide-oxide fusion bonding.

In some embodiments, the die 110 may be a logic die (e.g., centralprocessing unit (CPU), microcontroller, etc.), a memory die (e.g.,dynamic random access memory (DRAM) die, static random access memory(SRAM) die, etc.), a power management die (e.g., power managementintegrated circuit (PMIC) die), a radio frequency (RF) die, a sensordie, a micro-electro-mechanical-system (MEMS) die, a signal processingdie (e.g., digital signal processing (DSP) die), a front-end die (e.g.,analog front-end (AFE) die), or the like. In some embodiments, theconductive pads 112 are disposed over the semiconductor substrate 111.The passivation layer 113 is formed over the semiconductor substrate 111and has contact openings that partially expose the conductive pads 112.The semiconductor substrate 111 may be a silicon substrate includingactive components (e.g., transistors or the like) and passive components(e.g., resistors, capacitors, inductors or the like) formed therein. Theconductive pads 112 may be aluminum pads, copper pads, or other suitablemetal pads. The passivation layer 113 may be a silicon oxide layer, asilicon nitride layer, a silicon oxy-nitride layer, or a dielectriclayer formed by other suitable dielectric materials. Furthermore, thepost-passivation layer 114 is formed over the passivation layer 113. Thepost-passivation layer 114 covers the passivation layer 113 and has aplurality of contact openings. The conductive pads 112 are partiallyexposed by the contact openings of the post passivation layer 240. Thepost-passivation layer 114 may be a polyimide (PI) layer, apolybenzoxazole (PBO) layer, or a dielectric layer formed by othersuitable polymers. In addition, the conductive pillars 115 are formedextend through the contact openings in the post passivation layer 240and are mechanically and electrically coupled to the correspondingconductive pads 112. In some embodiments, the conductive pillars 115 maybe plated copper pillars. The protection layer 116 is formed on thepost-passivation layer 114 so as to cover the conductive pillars 115.The material of protection layer 116 may be a polymer such as PBO, PI,benzocyclobutene (BCB), or the like; a nitride such as silicon nitrideor the like; an oxide such as silicon oxide or the like; or acombination thereof. The protection layer 116 may be formed, forexample, by spin coating, lamination, chemical vapor deposition (CVD),or the like.

In some embodiments, in the direction Z, the die 110 has a thicknessless than a height of the conductive through vias 100, as shown in FIG.1G. However, the disclosure is not limited thereto. In some alternativeembodiments, in the direction Z, the thickness of the die 110 may begreater than or substantially equal to the height of the conductivethrough vias 100. As shown in FIG. 1G, the die 110 is picked and placedonto the buffer layer BL after the formation of the conductive throughvias 100. However, the disclosure is not limited thereto. In somealternative embodiments, one or more die(s) 200 may be picked and placedonto the buffer layer BL prior to the formation of the conductivethrough vias 100. In the exemplary embodiment, only one die 110 isillustrated in FIG. 1G. However, it should be noted that the number ofdie 110 placed on the buffer layer BL is not limited thereto, and thiscan be adjusted based on design requirement. In some embodiments, whenmore than one dies 200 are placed on the buffer layer BL, the dies 200may be arranged in an array, and when the dies 200 are arranged in anarray, the conductive through vias 100 may be classified into groups.

Referring to FIG. 1H, an encapsulant 120 is formed over the buffer layerBL to encapsulate the die 110, and the conductive through vias 100. Indetail, the encapsulant 120 is formed to fill the gaps between the die110 and the conductive through vias 100 and the gaps between theadjacent conductive through vias 100, so that the encapsulant 120 coversthe sidewalls and the illustrated top surfaces of the die 110 and theconductive through vias 100. That is to say, the die 110 and theconductive through vias 100 are embedded in the encapsulant 120, and arenot revealed. From another point of view, the encapsulant 120 may bereferred to as “gap-fill material”. In some embodiments, the material ofthe encapsulant 120 may include a molding compound, a molding underfill,a resin (such as epoxy), or the like. In some alternative embodiments,the material of the encapsulant 120 may include nitride such as siliconnitride, oxide such as silicon oxide, phosphosilicate glass (PSG),borosilicate glass (BSG), boron-doped phosphosilicate glass (BPSG), acombination thereof, or the like. In yet alternative embodiments, thematerial of each of the encapsulant 120 may be organic material (e.g.,epoxy, PI, PBO, or the like), or the mixture of inorganic and organicmaterials (e.g., the mixture of silicon oxide and epoxy, or the like).In some embodiments, the encapsulant 120 may be formed by a moldingprocess, such as a compression molding process. In some alternativeembodiments, the encapsulant 120 may be formed through suitablefabrication techniques such as CVD, high-density plasma chemical vapordeposition (HDPCVD) or plasma-enhanced chemical vapor deposition(PECVD).

Referring to FIG. 1I, a planarization process is then performed on theencapsulant 120, the die 110 and the conductive through vias 100 untilthe illustrated top surfaces of the conductive pillars 115 and theillustrated top surfaces of the conductive through vias 100 are exposed.After the planarization process is performed on the encapsulant 120, anencapsulant 120′ is formed over buffer layer BL. In some embodiments,the illustrated top surfaces of the conductive through vias 100, theconductive pillars 115, the protection layer 116, and the encapsulant120′ are substantially coplanar after the planarization process. In someembodiments, the planarization process may be, for example, achemical-mechanical polish (CMP), a grinding process, or the like. Insome embodiments, after the planarization process, a cleaning processmay be optionally performed. For example, the cleaning process ispreformed to clean and remove the residue generated from theplanarization process. However, the disclosure is not limited thereto,and the planarization process may be performed through any othersuitable method. The conductive through vias 100 penetrate theencapsulant 120′, and the conductive through vias 100 are referred to asthrough integrated fan-out vias.

Referring to FIG. 1J, after the planarization process, a redistributionlayer 130 is formed on the encapsulant 120′, the conductive through vias100 and the die 110. In some embodiments, the redistribution layer 130is formed on the illustrated top surfaces of the conductive through vias100, the conductive pillars 115, the protection layer 116, and theencapsulant 120′. That is, the redistribution layer 130 is formed on theencapsulant 120′ along the stacking direction (e.g. the direction Z) ofthe carrier C and the die 110. In some embodiments, the redistributionlayer 130 is electrically connected to the conductive through vias 100,and is electrically connected to the die 110 through the conductivepillars 115. In some embodiments, the die 110 is electrically connectedto the conductive through vias 100 through the redistribution layer 130.

Furthermore, in some embodiments, the formation of the redistributionlayer 130 includes sequentially forming one or more dielectric layers132, and one or more conductive layers 134 in alternation. In certainembodiments, the conductive layers 134 are sandwiched between thedielectric layers 132. Although three layers of the conductive layers134 and four layers of dielectric layers 132 are illustrated herein, thescope of the disclosure is not limited by the embodiments of thedisclosure. In other embodiments, the number of the conductive layers134 and the number of the dielectric layers 132 may be adjusted based onproduct requirement. In some embodiments, the conductive layers 134 areelectrically connected to the conductive pillars 115 of the die 110.Furthermore, the conductive layers 134 are electrically connected to theconductive through vias 100.

In some embodiments, the material of the dielectric layers 132 may bePI, PBO, BCB, a nitride such as silicon nitride, an oxide such assilicon oxide, PSG, BSG, BPSG, a combination thereof or the like, whichmay be patterned using a photolithography and/or etching process. Insome embodiments, the material of the dielectric layers 132 may beformed by suitable fabrication techniques such as spin-on coating, CVD,HDPCVD, PECVD, atomic layer deposition (ALD) or the like. In someembodiments, the material of the conductive layers 134 may be made ofconductive materials formed by electroplating or deposition, such asaluminum, titanium, copper, nickel, tungsten, and/or alloys thereof,which may be patterned using a photolithography and etching process. Insome embodiments, the conductive layers 134 may be patterned copperlayers or other suitable patterned metal layers.

After forming the redistribution layer 130, a plurality of conductivepads 140 are disposed on an exposed top surface of the topmost layer ofthe conductive layers 134. In certain embodiments, the conductive pads140 are, for example, under-ball metallurgy (UBM) patterns used for ballmount. As shown in FIG. 1J, the conductive pads 140 are formed on andelectrically connected to the redistribution layer 130. In someembodiments, the material of the conductive pads 140 may include copper,nickel, titanium, tungsten, or alloys thereof or the like, and may beformed by an electroplating process, for example. The number ofconductive pads 140 are not limited in this disclosure, and may beselected based on the design layout. In some alternative embodiments,the conductive pads 140 may be omitted. In other words, conductiveelements 142 (described hereinafter) formed in subsequent steps may bedirectly disposed on the redistribution layer 130.

After forming the conductive pads 140, a plurality of conductiveelements 142 is disposed on the conductive pads 140 and over theredistribution layer 130. In some embodiments, the conductive elements142 may be disposed on the conductive pads 140 by a ball placementprocess and/or reflow process, or other suitable forming method. In someembodiments, the conductive elements 142 may be ball grid array (BGA)connectors, solder balls, metal pillars, controlled collapse chipconnection (C4) bumps, micro bumps, electroless nickel-electrolesspalladium-immersion gold technique (ENEPIG) formed bumps, or the like.In some embodiments, the conductive elements 142 are connected to theredistribution layer 130 through the conductive pads 140. In certainembodiments, some of the conductive elements 142 may be electricallyconnected to the die 110 through the redistribution layer 130.Furthermore, some of the conductive elements 142 may be electricallyconnected to the conductive through vias 100 through the redistributionlayer 130. The number of the conductive elements 142 is not limited tothe disclosure, and may be designated and selected based on the numberof the conductive pads 140. The material of the conductive elements 142,for example, may include a conductive material such as solder, copper,aluminum, gold, nickel, silver, palladium, tin, or a combinationthereof. In one embodiment, the material of the conductive elements 142,for example, may be solder-free.

Referring to FIG. 1K, after forming the redistribution layer 130 andplacing the conductive elements 142 thereon, the structure shown in FIG.1J may be turned upside down and attached to a tape T (e.g., a dicingtape) supported by a frame F. In some embodiments, the conductiveelements 142 are in contact with tape T. As illustrated in FIG. 1K, thecarrier C is debonded and is separated from the buffer layer BL. In someembodiments, the de-bonding process includes projecting a light such asa laser light or an UV light on the de-bonding layer DB (e.g., the LTHCrelease layer) so that the carrier C can be easily removed along withthe de-bonding layer DB. During the de-bonding step, the tape T is usedto secure the package structure before de-bonding the carrier C and thede-bonding layer DB. After the de-bonding process, a backside surface(i.e., the illustrated top surface in FIG. 1K) of the buffer layer BL isrevealed or exposed.

Referring to both FIG. 1K and FIG. 1L, after the de-bonding process, adicing process is performed along dicing lines DL to cut the wholestructure shown in FIG. 1K (i.e., cutting through the buffer layer BL,the encapsulant 120′, and the redistribution layer 130) into a pluralityof package structures 10. The package structures 10 are referred to asintegrated fan-out (InFO) packages. In the exemplary embodiment, thedicing process is a wafer dicing process including mechanical bladesawing or laser cutting. In a subsequent process, the separated packagestructures 10 may, for example, be disposed onto a circuit substrate oronto other components based on requirements.

Although the steps of the method are illustrated and described as aseries of acts or events, it will be appreciated that the illustratedordering of such acts or events are not to be interpreted in a limitingsense. In addition, not all illustrated process or steps are required toimplement one or more embodiments of the present disclosure.

FIG. 4 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure. Theelements similar to or substantially the same as the elements describedpreviously will use the same reference numbers, and certain details ordescriptions (e.g. the materials, formation processes, positioningconfigurations, etc.) of the same elements would not be repeated herein.Referring to FIG. 4 , after fabricating a first package, such as thepackage structure 10 illustrated in FIG. 1L, a second package 200 may bestacked on the package structure 10 (first package) so as to form apackage-on-package (PoP) structure 20. As illustrated in FIG. 4 , thesecond package 200 is electrically connected to the conductive throughvias 100 of the package structure 10 (first package). In someembodiments, the second package 200 has a substrate 202, semiconductordies 204, bonding wires 206, conductive pads 208, conductive pads 212,and an encapsulant 210. In some embodiments, the semiconductor dies 204are mounted on the illustrated top surface of the substrate 202 shown inFIG. 4 . In some embodiments, the bonding wires 206 are used to provideelectrical connections between the semiconductor dies 204 and theconductive pads 208 (such as bonding pads). In some embodiments, theencapsulant 210 is formed to encapsulate and protect the semiconductordies 204 and the bonding wires 206. In some embodiments, interconnects(not shown) or conductive through vias (not shown) embedded in thesubstrate 202 may be used to provide electrical connections between theconductive pads 208 and the conductive pads 212 (such as bonding pads).In some embodiments, the conductive pads 208 and the conductive pads 212are respectively disposed on two opposite surfaces of the substrate 202,as shown in FIG. 4 . In certain embodiments, the conductive pads 212 areelectrically connected to the semiconductor dies 204 through theinterconnects (not shown) or the conductive through vias (not shown). Insome embodiments, the conductive pads 212 of the package structure 200are electrically connected to conductive elements 214. Furthermore, theconductive elements 214 are electrically connected to the conductivethrough vias 100 of the package structure 10 (first package). In someembodiments, an underfill 216 is further provided to fill the gapbetween the second package 200 on the package structure 10 (firstpackage) to protect the conductive elements 214. Owing to the underfill216, a bonding strength between the second package 200 and the packagestructure 10 (first package) are enhanced, thereby improving thereliability of the package structure depicted in FIG. 4 . After stackingthe second package 200 on the package structure 10 (first package) andproviding electrical connection therebetween, the package-on-packagestructure 20 can be fabricated.

FIG. 5 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure. Theelements similar to or substantially the same as the elements describedpreviously will use the same reference numbers, and certain details ordescriptions (e.g. the materials, formation processes, positioningconfigurations, etc.) of the same elements would not be repeated herein.Referring to FIG. 5 , in some embodiments, a package component 300 isprovided, where the package-on-package structure 20 depicted in FIG. 4is bonded on the package component 300 to form the package structurehaving a stacked structure. In some embodiments, the package component300 includes conductive pads 302. In some embodiments, the packagecomponent 300 is a package substrate, which may be a coreless substrateor a substrate having a core. In some alternative embodiments, thepackage component 300 is a printed circuit board or a package. In someembodiments, as shown in FIG. 5 , the conductive elements 142 of thepackage structure 10 in the package-on-package structure 20 are bondedto the conductive pads 302 (such as bonding pads) to provide electricalconnections between the package component 300 and the package-on-packagestructure 20. That is to say, the package-on-package structure 20 isphysically and electrically connected to the package component 300. Insome embodiments, an underfill (not shown) may be applied to fill thegap between the package-on-package structure 20 and the packagecomponent 300 to protect the conductive elements 142 and the conductivepads 140, which enhances the bonding strength between thepackage-on-package structure 20 and the package component 300; therebyimproving the reliability of the package structure depicted in FIG. 5 .

FIG. 6 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure. Thepackage structure 40 illustrated in FIG. 6 is similar to the packagestructure 10 illustrated in FIG. 1L, hence the same reference numeralsare used to refer to the same or liked parts, and its detaileddescription will be omitted herein. The differences between the packagestructure 40 illustrated in FIG. 6 and the package structure 10illustrated in FIG. 1L will be described below.

Referring to FIG. 6 , in the package structure 40, the conductivepillars 400 are disposed on an exposed top surface of the topmost layerof the conductive layers 134. In some embodiments, the material of theconductive pillars 400, for example, may include a conductive materialsuch as copper, aluminum, titanium, nickel, tungsten, tin, solder or acombination thereof. In certain embodiments, the conductive pillars 400may be plated copper pillars. Furthermore, referring to both FIG. 6 andFIG. 1L, the conductive pillars 400 are used in replacement of theconductive pads 140 for providing electrical connection between theconductive elements 142 and the redistribution layer 130.

In the package structure 10 illustrated in FIG. 1L, only one die 110 isdisposed between the conductive through vias 100. However, thedisclosure is not limited thereto. In some alternative embodiments, morethan one die 110 may be disposed between the conductive through vias100. Hereinafter, other embodiments will be described with reference toFIG. 7 .

FIG. 7 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure. Thepackage structure 50 illustrated in FIG. 7 is similar to the packagestructure 10 illustrated in FIG. 1L, hence the same reference numeralsare used to refer to the same or liked parts, and its detaileddescription will be omitted herein. Referring to FIG. 7 and FIG. 1L, thedifferences between the package structure 50 illustrated in FIG. 7 andthe package structure 10 illustrated in FIG. 1L lies in that two dies110 are disposed between the conductive through vias 100 in the packagestructure 50. However, the disclosure is not limited thereto. In somealternative embodiments, more number of dies 110 may be formed based ondesign requirement.

FIG. 8 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure. Thepackage structure 60 illustrated in FIG. 8 is similar to the packagestructure 10 illustrated in FIG. 1L, hence the same reference numeralsare used to refer to the same or liked parts, and its detaileddescription will be omitted herein. The differences between the packagestructure 60 illustrated in FIG. 8 and the package structure 10illustrated in FIG. 1L will be described below.

Referring to FIG. 8 , another redistribution layer 600 is included inthe package structure 60. In some embodiments, as shown in FIG. 8 , theredistribution layer 600 and the redistribution layer 130 arerespectively disposed on two opposite surfaces of the encapsulant 120′.That is to say, the die 110 is disposed between the redistribution layer600 and the redistribution layer 130. In some embodiments, as shown inFIG. 8 , the formation of the redistribution layer 600 includessequentially forming one or more dielectric layers 602 and one or moreconductive layers 604 in alternation. Although FIG. 8 illustrates thatthe redistribution layer 600 includes two dielectric layers 602 and oneconductive layer 604, where the conductive layer 604 is sandwichedbetween the dielectric layers 602, the disclosure is not limitedthereto. In other embodiments, the number of the dielectric layers 602and the number of the conductive layer 604 may be adjusted based onproduct requirement. In some embodiments, the conductive through vias100 are electrically connected to the conductive layer 604 of theredistribution layer 600. That is to say, in the package structure 60,the conductive through vias 100 may used to provide electricalconnections between the redistribution layer 130 and the redistributionlayer 600. In some embodiments, the materials of the dielectric layer602 and the conductive layer 604 of the redistribution layer 600 issimilar to the materials of the dielectric layer 132 and the conductivelayer 134 mentioned for the redistribution layer 130. Therefore, thedetailed descriptions of the dielectric layer 602 and the conductivelayer 604 will be omitted herein. Furthermore, referring to both FIG. 8and FIG. 1L, the redistribution layer 600 is disposed on the encapsulant120′ in replacement of the buffer layer BL.

FIG. 9 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure. Thepackage structure 70 illustrated in FIG. 9 is similar to the packagestructure 10 illustrated in FIG. 1L, hence the same reference numeralsare used to refer to the same or liked parts, and its detaileddescription will be omitted herein. The differences between the packagestructure 70 illustrated in FIG. 9 and the package structure 10illustrated in FIG. 1L will be described below.

Referring to both FIG. 9 and FIG. 1L, the main difference between thepackage structure 70 and the package structure 10 lies in that a die 700is further included in the package structure 70. In the exemplaryembodiment, the die 700 includes a semiconductor substrate 701, aplurality of conductive pads 702, a passivation layer 703, apost-passivation layer 704, a plurality of conductive pillars 705, and aprotection layer 706. These elements of the die 700 may be similar tothe semiconductor substrate 111, the conductive pads 112, thepassivation layer 113, the post-passivation layer 114, the conductivepillars 115, and the protection layer 116 of the die 110, hence thedetailed descriptions of the said elements of the die 700 may bereferred thereto. Briefly, the conductive pads 702 are located on thesemiconductor substrate 701, the passivation layer 703 and thepost-passivation layer 704 are sequentially located on the semiconductorsubstrate 701 and the conductive pads 702, the protection layer 706 islocated on the post-passivation layer 704, the conductive pillars 705are embedded in the post-passivation layer 704 and the protection layer706, and the conductive pillars 705 are electrically connected with theconductive pads 702. As illustrated in FIG. 9 , the die 700 is locatedover the die 110 along the direction Z.

In some embodiments, as shown in FIG. 9 , an encapsulant 710 is formedto encapsulate the die 700. The encapsulant 710 may be similar to theencapsulant 120′, hence the detailed descriptions of the encapsulant 710may be referred thereto. In some embodiments, as shown in FIG. 9 ,conductive through vias 720 are embedded within the encapsulant 710. Theconductive through vias 720 may be similar to the conductive throughvias 100, hence the detailed descriptions of the conductive through vias720 may be referred thereto. Briefly, as mentioned above, by applyingthe stripping solution including the alkaline compound and thenon-dimethyl sulfoxide solvent containing the aprotic solvent and theprotic solvent in the stripping process, the conductive through vias 720having high aspect ratio can be formed with significantly improvedmanufacturing yield. Also, as mentioned above, by applying the strippingsolution including the alkaline compound and the non-dimethyl sulfoxidesolvent containing the aprotic solvent and the protic solvent in thestripping process, the conductive through vias 720 can be formed to havehigh distribution density.

In some embodiments, as shown in FIG. 9 , an interconnection layer 730is disposed between the encapsulant 710 and the encapsulant 120′. Insome embodiments, the interconnection layer 730 includes aninter-dielectric layer 732 and a plurality of conductive layers 734. Insome embodiments, the conductive layers 734 are embedded in theinter-dielectric layer 732. For simplicity, the inter-dielectric layer732 is illustrated as a bulky layer in FIG. 9 , but it should beunderstood that the inter-dielectric layer 732 may be constituted bymultiple dielectric layers, and the number of the dielectric layers inthe inter-dielectric layer 732 may be adjusted depending on productrequirement. Further, the conductive layers 734 and the dielectriclayers of the inter-dielectric layer 732 may be stacked alternately. Itshould be noted that the number of the conductive layers 734 shown inFIG. 9 is merely an illustration, and the disclosure is not limited. Insome alternative embodiments, the number of the conductive layers 734may be adjusted based on product requirement.

In some embodiments, the material of the inter-dielectric layer 732 maybe PI, PBO, BCB, a nitride such as silicon nitride, an oxide such assilicon oxide, PSG, BSG, BPSG, a combination thereof or the like, whichmay be patterned using a photolithography and/or etching process. Insome embodiments, the material of the inter-dielectric layer 732 may beformed by suitable fabrication techniques such as spin-on coating, CVD,HDPCVD, PECVD, ALD or the like. In some embodiments, the material of theconductive layers 734 may be made of conductive materials formed byelectroplating or deposition, such as aluminum, titanium, copper,nickel, tungsten, and/or alloys thereof, which may be patterned using aphotolithography and etching process. In some embodiments, theconductive layers 734 may be patterned copper layers or other suitablepatterned metal layers.

In some embodiments, as shown in FIG. 9 , the interconnection layer 730is electrically connected to the conductive through vias 100, theconductive pillars 115 of the die 110, and the conductive through vias720. In some embodiments, the die 110 is electrically connected to theconductive through vias 100 through the interconnection layer 730. Insome embodiments, as shown in FIG. 9 , the die 700 is attached (oradhered) to the inter-dielectric layer 732 in the interconnection layer730 through a bonding film D1. In some embodiments, the bonding film D1may be an adhesive film, such as a die attach film (DAF). In somealternative embodiments, the bonding film D1 may be any materials usedfor fusion bonding. For example, the bonding film D1 may be anoxide-based film (e.g., silicon oxide film) used for oxide-oxide fusionbonding. In some embodiments, as shown in FIG. 9 , the redistributionlayer 130 is electrically connected to the conductive pillars 705 of thedie 700, and the conductive through vias 720. Furthermore, in someembodiments, the die 110 and the die 700 may be in different sizes(e.g., different heights and/or surface areas). In some alternativeembodiments, the die 110 and the die 700 may be in the same size (e.g.,same heights and/or surface areas).

FIG. 10 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure. Thepackage structure 80 illustrated in FIG. 10 is similar to the packagestructure 10 illustrated in FIG. 1L, hence the same reference numeralsare used to refer to the same or liked parts, and its detaileddescription will be omitted herein. The differences between the packagestructure 80 illustrated in FIG. 10 and the package structure 10illustrated in FIG. 1L will be described below.

Referring to both FIG. 10 and FIG. 1L, the main difference between thepackage structure 80 and the package structure 10 lies in that the die110 is omitted from the package structure 80. In detail, referring toboth FIG. 10 and FIG. 1L, a package 800 is encapsulated by theencapsulant 120′ in replacement of the die 110. In the exemplaryembodiment, the package 800 includes a first die 810, a second die 820,an encapsulant 830 and conductive through vias 840. As illustrated inFIG. 10 , the second die 820 is stacked on the first die 810 along thedirection Z. In other words, multiple dies 810, 820 are integrated intoa single package 800. As such, the package 800 may be referred to as a“system on integrated circuit (SOIC) package.” In some embodiments, asshown in FIG. 10 , the package 800 is attached (or adhered) to thebuffer layer BL through a bonding film D2. In some embodiments, thebonding film D2 may be an adhesive film, such as a die attach film(DAF). In some alternative embodiments, the bonding film D2 may be anymaterials used for fusion bonding. For example, the bonding film D2 maybe an oxide-based film (e.g., silicon oxide film) used for oxide-oxidefusion bonding.

In some embodiments, the first die 810 may include a semiconductorsubstrate 811, a plurality of conductive pads 812, a passivation layer813, a post-passivation layer 814, a conductive layer 815, and adielectric layer 816, as shown in FIG. 10 . The semiconductor substrate,the conductive pads 812, the passivation layer 813 and thepost-passivation layer 814 of the first die 810 may be similar to thesemiconductor substrate 111, the conductive pads 112, the passivationlayer 113 and the post-passivation layer 114 of the die 110, hence thedetailed descriptions of the said elements may be referred thereto.Briefly, the conductive pads 812 are located on the semiconductorsubstrate 811, and the passivation layer 813 and the post-passivationlayer 814 are sequentially located on the semiconductor substrate 811and the conductive pads 812. In some embodiments, as shown in FIG. 10 ,the conductive layer 815 is disposed on the post-passivation layer 814and electrically connected with the conductive pads 812 through thecontact openings of the post-passivation layer 814. In some embodiments,the material of the conductive layer 815, for example, may include aconductive material such as copper, aluminum, titanium, nickel,tungsten, tin, solder, or a combination thereof. In some embodiments,the conductive layer 815 may be formed by, for example, electroplating,deposition, and/or photolithography and etching. In some embodiments, asshown in FIG. 10 , the dielectric layer 816 is disposed on theconductive layer 815. In some embodiments, the material of thedielectric layer 816 may be PI, PBO, BCB, a nitride such as siliconnitride, an oxide such as silicon oxide, PSG, BSG, BPSG, a combinationthereof or the like, which may be patterned using a photolithographyand/or etching process. In some embodiments, the material of thedielectric layer 816 may be formed by suitable fabrication techniquessuch as spin-on coating, CVD, HDPCVD, PECVD, atomic layer deposition(ALD) or the like. The illustrated top surface of the dielectric layer816, which is opposite to the illustrated bottom surface contacting theconductive layer 815, may be levelled and may have a high degree ofplanarity.

In some embodiments, the second die 820 may include a semiconductorsubstrate 821, a plurality of conductive pads 822, a passivation layer823, a post-passivation layer 824, a plurality of conductive pillars825, and a protection layer 826, as shown in FIG. 10 . These elements ofthe second die 820 may be similar to the semiconductor substrate 111,the conductive pads 112, the passivation layer 113, the post-passivationlayer 114, the conductive pillars 115, and the protection layer 116 ofthe die 110, hence the detailed descriptions of the said elements of thesecond die 820 may be referred thereto. Briefly, the conductive pads 822are located on the semiconductor substrate 821, the passivation layer823 and the post-passivation layer 824 are sequentially located on thesemiconductor substrate 821 and the conductive pads 822, the protectionlayer 826 is located on the post-passivation layer 824, the conductivepillars 825 are embedded in the post-passivation layer 824 and theprotection layer 826, and the conductive pillars 825 are electricallyconnected with the conductive pads 822. Moreover, in some embodiments,as shown in FIG. 10 , the second die 820 is attached (or adhered) to thedielectric layer 816 on first die 810 through a bonding film D3. In someembodiments, the bonding film D3 may be an adhesive film, such as a dieattach film (DAF). In some alternative embodiments, the bonding film D3may be any materials used for fusion bonding. For example, the bondingfilm D3 may be an oxide-based film (e.g., silicon oxide film) used foroxide-oxide fusion bonding.

In some embodiments, as shown in FIG. 10 , an encapsulant 830 is formedto encapsulate the die 820. The encapsulant 830 may be similar to theencapsulant 120′, hence the detailed descriptions of the encapsulant 830may be referred thereto. In some embodiments, as shown in FIG. 10 ,conductive through vias 840 are embedded within the encapsulant 830. Insome embodiments, each conductive through via 840 is formed to have around top-view shape. However, the disclosure is not limited thereto. Insome alternative embodiments, each conductive through via 840 mayexhibit a polygonal shape or other suitable shapes from the top view. Insome embodiments, in the direction Z, a height H₂ of each conductivethrough via 840 ranges between about 15 μm and about 360 μm. In someembodiments, in the direction X perpendicular the direction Z, a widthW₂ of each conductive through via 840 ranges between about 5 μm andabout 120 μm. In the case that each conductive through via 840 has around top-view shape, then the width W₂ may be the diameter. In the casethat each conductive through via 840 has a polygonal shape from the topview, then the width W₂ may be the maximum dimension. In someembodiments, an aspect ratio (i.e., a ratio of the height H₂ to thewidth W₂) of each conductive through via 840 is in a range from morethan about 3 to about 15. According to the descriptions with respect toFIGS. 1A-1L, and 3A-3E, it may be deduced that the method describedabove in conjunction with FIGS. 3A-3E can be applied to themanufacturing process of any package structure that includes conductivethrough vias, even the conductive through vias having high aspect ratio.As such, those skilled in the art should understand that the methoddescribed above in conjunction with FIGS. 3A-3E can be applied tomanufacture the conductive through vias 840, thereby whether theconductive through vias 840 have high aspect ratio or not, theconductive through vias 840 can be formed with significantly improvedmanufacturing yield. However, the disclosure is not limited thereto.

In some embodiments, as shown in FIG. 10 , the conductive through vias840 is electrically connected to the conductive layer 815 of the firstdie 810. In some embodiments, as shown in FIG. 10 , the redistributionlayer 130 is electrically connected to the conductive through vias 100,the conductive pillars 825 of the second die 820, and the conductivethrough vias 840. In some embodiments, the second die 820 iselectrically connected to the first die 810 through the redistributionlayer 130 and the conductive through vias 840. In some embodiments, thepackage 800 is electrically connected to the conductive through vias 100through the redistribution layer 130.

FIG. 11 is a schematic sectional view of a package structure inaccordance with some alternative embodiments of the disclosure.

Referring to FIG. 11 , a package structure 90 may include a package P, acarrier die 950, an underfill 960, an encapsulant 970, a redistributionlayer 980, a plurality of conductive pads 990 and a plurality ofconductive elements 992. In the exemplary embodiment, the package Pincludes a tier structure T₁, a tier structure T₂, a tier structure T₃,a tier structure T₄, and a plurality of conductive terminals 940.Although FIG. 11 illustrates that the package P includes four tierstructures (i.e., the tier structures T₁ to T₄), the disclosure is notlimited thereto. In other embodiments, the number of the tier structuresin the package P may be adjusted based on product requirement.

As illustrated in FIG. 11 , each of the tier structure T₁, the tierstructure T₂, the tier structure T₃ and the tier structure T₄ includesdies 900, an encapsulant 910 and a redistribution layer 930. Further, asillustrated in FIG. 11 , each of the tier structure T₂, the tierstructure T₃ and the tier structure T₄ includes conductive through vias920. In some embodiments, as shown in FIG. 11 , each die 900 may includea semiconductor substrate 901, a plurality of conductive pillars 905,and a protection layer 906. These elements of the die 900 may be similarto the semiconductor substrate 111, the conductive pillars 115, and theprotection layer 116 of the die 110, hence the detailed descriptions ofthe said elements of the die 900 may be referred thereto. In someembodiments, each die 900 may further include an interconnect structure(not shown), conductive pads (not shown), a passivation layer (notshown), and a post-passivation layer (not shown). In some embodiments,each die 900 may be a memory die (e.g., a DRAM die, a SRAM die, asynchronous dynamic random access memory (SDRAM), a NAND flash, etc.).Although FIG. 11 illustrates that each of the tier structure T₁, thetier structure T₂, the tier structure T₃ and the tier includes two dies900, the disclosure is not limited thereto. In other embodiments, thenumber of the dies 900 included in a tier structure may be adjustedbased on product requirement. Moreover, as shown in FIG. 11 , the tierstructure T₁ includes two separated dies 900. However, the disclosure isnot limited thereto. In some alternative embodiments, the tier structureT₁ may include a single one die 900.

In some embodiments, as shown in FIG. 11 , in each of the tier structureT₁, the tier structure T₂, the tier structure T₃ and the tier structureT₄, the encapsulant 910 is formed to encapsulate the dies 900. Theencapsulant 910 may be similar to the encapsulant 120′, hence thedetailed descriptions of the encapsulant 910 may be referred thereto.

In some embodiments, as shown in FIG. 11 , in each of the tier structureT₂, the tier structure T₃ and the tier structure T₄, the conductivethrough vias 920 are embedded within the encapsulant 910. In someembodiments, each conductive through via 904 is formed to have a roundtop-view shape. However, the disclosure is not limited thereto. In somealternative embodiments, each conductive through via 904 may exhibit apolygonal shape or other suitable shapes from the top view. In someembodiments, in the direction Z, a height H₃ of each conductive throughvia 904 ranges between about 15 μm and about 360 μm. In someembodiments, in the direction X perpendicular the direction Z, a widthW₃ of each conductive through via 904 ranges between about 5 μm andabout 120 μm. In the case that each conductive through via 904 has around top-view shape, then the width W₃ may be the diameter. In the casethat each conductive through via 904 has a polygonal shape from the topview, then the width W₃ may be the maximum dimension. In someembodiments, an aspect ratio (i.e., a ratio of the height H₃ to thewidth W₃) of each conductive through via 904 is more than about 3, i.e.,the conductive through vias 920 are formed to have high aspect ratio.According to the descriptions with respect to FIGS. 1A-1L, and 3A-3E, itmay be deduced that the method described above in conjunction with FIGS.3A-3E can be applied to the manufacturing process of any packagestructure that includes conductive through vias having high aspectratio. Accordingly, those skilled in the art should understand that themethod described above in conjunction with FIGS. 3A-3E can be applied tomanufacture the conductive through vias 920, thereby the conductivethrough vias 920 having high aspect ratio can be formed withsignificantly improved manufacturing yield.

In some embodiments, as shown in FIG. 11 , in each of the tier structureT₁, the tier structure T₂, the tier structure T₃ and the tier structureT₄, the redistribution layer 930 is formed on the encapsulant 910 andthe dies 900. In the exemplary embodiment, the redistribution layer 930includes a dielectric layer 932 and a plurality of conductive layers934. These elements of the redistribution layer 930 may be similar tothe dielectric layers 132 and the conductive layers 134 of theredistribution layer 130, hence the detailed descriptions of the saidelements of the redistribution layer 930 may be referred thereto. Forsimplicity, the dielectric layer 932 is illustrated as a bulky layer inFIG. 11 , but it should be understood that the dielectric layer 932 maybe constituted by multiple dielectric layers, and the number of thedielectric layers in the dielectric layer 932 may be adjusted dependingon product requirement. Further, the conductive layers 934 and thedielectric layers of the dielectric layer 932 may be stackedalternately. It should be noted that the number of the conductive layers934 shown in FIG. 11 is merely an illustration, and the disclosure isnot limited. In some alternative embodiments, the number of theconductive layers 934 may be adjusted based on product requirement.

In some embodiments, as shown in FIG. 11 , the redistribution layer 930of the tier structure T₁ is electrically connected to the dies 900 ofthe tier structure T₁ and the conductive through vias 920 of the tierstructure T₂; the redistribution layer 930 of the tier structure T₂ iselectrically connected to the dies 900 of the tier structure T₂, theconductive through vias 920 of the tier structure T₂ and the conductivethrough vias 920 of the tier structure T₃; the redistribution layer 930of the tier structure T₃ is electrically connected to the dies 900 ofthe tier structure T₃, the conductive through vias 920 of the tierstructure T₃ and the conductive through vias 920 of the tier structureT₄; the redistribution layer 930 of the tier structure T is electricallyconnected to the dies 900 of the tier structure T₄ and the conductivethrough vias 920 of the tier structure T₄. In some embodiments, as shownin FIG. 11 , each die 900 in the tier structure T₂ is attached (oradhered) to the redistribution layer 930 of the tier structure T₁through a bonding film D4; each die 900 in the tier structure T₃ isattached (or adhered) to the redistribution layer 930 of the tierstructure T₂ through a bonding film D5; each die 900 in the tierstructure T₄ is attached (or adhered) to the redistribution layer 930 ofthe tier structure T₃ through a bonding film D6. In some embodiments,each of the bonding film D4, the bonding film D5 and the bonding film D6may be an adhesive film, such as a die attach film (DAF). In somealternative embodiments, each of the bonding film D4, the bonding filmD5 and the bonding film D6 may be any materials used for fusion bonding.For example, each of the bonding film D4, the bonding film D5 and thebonding film D6 may be an oxide-based film (e.g., silicon oxide film)used for oxide-oxide fusion bonding.

In some embodiments, as shown in FIG. 11 , the conductive terminals 940are formed at the exposed surfaces of the redistribution layer 930 inthe tier structure T₁. The conductive terminals 940 may be formed byusing, for example, a sputtering, printing, plating, deposition, or thelike. The conductive terminals 940 may be formed of conductivematerial(s) including copper, aluminum, gold, nickel, silver, palladium,tin, solder, metal alloy, the like, or combinations thereof. In theexemplary embodiment, each of the conductive terminals 940 includes abump 942 and a metal cap 944 formed on the bump 942, as shown in FIG. 11. The bump 942 may be a micro-bump, a metal pillar, an ENEPIG formedbump, a C4 bump, a BGA bump, or the like. In an embodiment in which thebumps 942 are micro-bumps, a bump pitch between two adjacent bumps 942ranges from about 20 μm to about 140 μm. The bumps 31 may be solder freeand may have substantially vertical sidewalls. In some embodiments, themetal cap 32 is formed by, for example, plating, printing, or the like.For example, the material of the metal caps 944 includes nickel, tin,tin-lead, gold, silver, palladium, nickel-palladium-gold, nickel-gold,the like, or any combination of these.

In some embodiments, the carrier die 950 may be a logic die (e.g., CPU,microcontroller, a system-on-a-chip (SoC), a graphics processing unit(GPU), etc.). In some embodiments, the carrier die 950 may be used toprovide control functionality for the dies 900 in the tier structures T₁to T₄. In the exemplary embodiment, the carrier die 950 includes asemiconductor substrate 952, a plurality of conductive through vias 954and a plurality of conductive pads 956. The semiconductor substrate 952may be similar to the semiconductor substrate 111 of the die 110, hencethe detailed descriptions of the semiconductor substrate 952 may bereferred thereto. As illustrated in FIG. 11 , the conductive throughvias 954 penetrate the semiconductor substrate 952. The conductivethrough vias 954 may be formed by the following steps. First, openingsare formed in the semiconductor substrate 952 by, for example, etching,milling, laser techniques, or a combination thereof. Then, a thindielectric material may be formed in the openings by using, for example,an oxidation technique. A barrier layer may then be conformallydeposited over the semiconductor substrate 952 and in the openings. Thematerial of the barrier layer may include a nitride or an oxynitride,such as titanium nitride, titanium oxynitride, tantalum nitride,tantalum oxynitride, tungsten nitride, or a combination thereof. Next, aconductive material may be deposited over the barrier layer and in theopenings. The conductive material may be formed by an electro-chemicalplating process, CVD, ALD, PVD, or a combination thereof. Examples ofthe conductive material are copper, tungsten, aluminum, silver, gold, ora combination thereof. Afterward, the conductive material and thebarrier layer outside the openings are removed from the semiconductorsubstrate 952 by, for example, CMP. Thus, the conductive through vias954 may include a conductive material and a barrier layer between theconductive material and the semiconductor substrate 952.

In some embodiments, as shown in FIG. 11 , the conductive terminals 940of the package P are physically connecting the conductive pads 956 (suchas bonding pads) of the carrier die 950 by flip-chip bonding to provideelectrical connections between the package P and the carrier die 950.That is to say, the package P is physically and electrically connectedto the carrier die 950 through the conductive terminals 940 and theconductive pads 956. In some embodiments, as shown in FIG. 11 , theconductive through vias 954 are electrically connected to the conductivepads 956.

In some embodiments, as shown in FIG. 11 , the underfill 960 is providedto fill the gap between the package P and the carrier die 950. As shownin FIG. 11 , the underfill 960 may extend up along the sidewall of thepackage P. Owing to the underfill 960, a bonding strength between thepackage P and the carrier die 950 are enhanced, thereby improving thereliability of the package structure 90 depicted in FIG. 11 . In someembodiments, as shown in FIG. 11 , the encapsulant 970 is formed toencapsulate the package P and the underfill 960. The encapsulant 970 maybe similar to the encapsulant 120′, hence the detailed descriptions ofthe encapsulant 970 may be referred thereto.

In some embodiments, as shown in FIG. 11 , the redistribution layer 980is formed on the semiconductor substrate 952 of the carrier die 950 andopposite to the package P. The redistribution layer 980 may be formed ina manner similar to the redistribution layer 130, hence the detaileddescriptions of the redistribution layer 980 may be referred thereto. Insome embodiments, as shown in FIG. 11 , the conductive pads 990 and theconductive elements 992 are formed on the redistribution layer 980 andopposite to the carrier die 950. The conductive pads 990 and theconductive elements 992 may be similar to the conductive pads 140 andthe conductive elements 142, hence the detailed descriptions of theconductive pads 990 and the conductive elements 992 may be referredthereto. In some embodiments, the redistribution layer 980 is used toprovide electrical connections between the conductive pads 990 and theconductive through vias 954.

In accordance with some embodiments of the disclosure, a method forremoving a resist layer including the following steps is provided. Apatterned resist layer on a material layer is formed. A strippingsolution is applied to the patterned resist layer to dissolve thepatterned resist layer without dissolving the material layer, whereinthe stripping solution comprises a non-dimethyl sulfoxide solvent and analkaline compound, the non-dimethyl sulfoxide solvent comprises anaprotic solvent and a protic solvent.

In accordance with some alternative embodiments of the disclosure, amethod of manufacturing a semiconductor structure including thefollowing steps is provided. A seed layer is formed. A patterned masklayer is formed on the seed layer, wherein the patterned mask layer hasopenings exposing the seed layer. Metal patterns are formed in theopenings. A stripping process is performed to the patterned mask layerby applying a stripping solution to break the patterned mask layer intopieces and dissolve the pieces of the patterned mask layer in thestripping solution, wherein the stripping solution comprises anon-dimethyl sulfoxide solvent and an alkaline compound, thenon-dimethyl sulfoxide solvent comprises an aprotic solvent and a proticsolvent.

In accordance with some alternative embodiments of the disclosure, amethod of manufacturing a semiconductor structure including thefollowing steps is provided. Conductive through vias are formed on acarrier. A die is provided on the carrier. The die and the conductivethrough vias are laterally encapsulated with an encapsulant, whereinforming the conductive through vias on the carrier includes:sequentially forming a seed layer and a resist layer on the carrier;patterning the resist layer to form openings exposing the seed layer;forming metal patterns in the openings; and performing a strippingprocess with a stripping solution to remove the patterned resist layer,wherein the stripping solution comprises a non-dimethyl sulfoxidesolvent and an alkaline compound, the non-dimethyl sulfoxide solventcomprises an aprotic solvent and a protic solvent.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A method for removing a resist layer, comprising:forming a patterned mask layer on a material layer; and applying astripping solution to the patterned mask layer to dissolve the patternedmask layer without dissolving the material layer, wherein the strippingsolution comprises a non-dimethyl sulfoxide solvent and an alkalinecompound, wherein the alkaline compound comprises a mixture of potassiumhydroxide (KOH) and sodium hydroxide (NaOH).
 2. The method according toclaim 1, wherein the non-dimethyl sulfoxide solvent comprisesN-methylpyrrolidone (NMP), tetrahydrofuran (THF), dimethylformamide(DMF), acetonitrile (MeCN) or dichloromethance (DCM).
 3. The methodaccording to claim 1, wherein the non-dimethyl sulfoxide solventcomprises an alkanolamine solvent.
 4. The method according to claim 3,wherein the alkanolamine solvent comprises ethanol amine (MEA), methylethanol 2-(2-aminoethylamino)ethanol, or diethanolamine.
 5. The methodaccording to claim 1, wherein the alkaline compound further comprisestetra-methyl ammonium hydroxide (TMAH).
 6. The method according to claim1, wherein a material of the patterned mask layer comprises an estergroup-containing resist material.
 7. A method of manufacturing asemiconductor structure, comprising: forming a seed layer; forming apatterned resist layer on the seed layer, wherein the patterned resistlayer has openings exposing the seed layer; forming metal patterns inthe openings; and performing a stripping process to the patterned resistlayer by applying a stripping solution to break the patterned resistlayer into pieces and dissolve the pieces of the patterned resist layerin the stripping solution, wherein the stripping solution comprises anon-dimethyl sulfoxide solvent and an alkaline compound, thenon-dimethyl sulfoxide solvent comprises an aprotic solvent and a proticsolvent, wherein a ratio of an amount of the aprotic solvent to anamount of the protic solvent ranges from 1:3.5 to 3.5:1, the aproticsolvent comprises N-methylpyrrolidone (NMP), tetrahydrofuran (THF),dimethylformamide (DMF), acetonitrile (MeCN) or dichloromethance (DCM),the protic solvent comprises ethanol amine (MEA), methyl ethanol amine,2-(2-aminoethylamino)ethanol, or diethanolamine, the alkaline compoundcomprises tetra-methyl ammonium hydroxide (TMAH), potassium hydroxide(KOH), sodium hydroxide (NaOH) or a combination thereof, and based on atotal weight of the stripping solution, an amount of the aprotic solventis 20 wt % to 70 wt %, an amount of the protic solvent is 20 wt % to 70wt %, an amount of the alkaline compound is 0.5 wt % to 5.5 wt %, andwherein the alkaline compound comprises a mixture of TMAH and KOH. 8.The method according to claim 7, wherein the metal patterns are formedwith a pitch of two adjacent metal patterns in a range of 30 μm to 120μm.
 9. The method according to claim 7, wherein a swelling percentage byvolume of the patterned resist layer during the stripping process isapproaching 0%.
 10. The method according to claim 7, wherein during thestripping process, the alkaline compound permeates into the patternedresist layer to break a crosslinked structure of the patterned resistlayer.
 11. The method according to claim 7, wherein at least one of themetal patterns is formed with an aspect ratio (height to width) morethan
 3. 12. A method of manufacturing a semiconductor structure,comprising: forming conductive through vias on a carrier; providing adie on the carrier; and laterally encapsulating the die and theconductive through vias with an encapsulant, wherein forming theconductive through vias on the carrier comprises: sequentially forming aseed layer and a resist layer on the carrier, wherein a material of theresist layer comprises an ester group-containing resist material;patterning the resist layer to form openings exposing the seed layer;forming metal patterns in the openings; and performing a strippingprocess with a stripping solution to remove the patterned resist layer,wherein the stripping solution comprises a non-dimethyl sulfoxidesolvent and an alkaline compound, the non-dimethyl sulfoxide solventcomprises an aprotic solvent and a protic solvent.
 13. The methodaccording to claim 12, wherein the aprotic solvent comprisesN-methylpyrrolidone (NMP), tetrahydrofuran (THF), dimethylformamide(DMF), acetonitrile (MeCN) or dichloromethance (DCM), the protic solventcomprises ethanol amine (MEA), methyl ethanol amine,2-(2-aminoethylamino)ethanol, or diethanolamine, the alkaline compoundcomprises tetra-methyl ammonium hydroxide (TMAH), potassium hydroxide(KOH) or a combination thereof, and based on a total weight of thestripping solution, an amount of the aprotic solvent is 20 wt % to 70 wt%, an amount of the protic solvent is 20 wt % to 70 wt %, an amount ofthe alkaline compound is 0.5 wt % to 5.5 wt %.
 14. The method accordingto claim 12, wherein forming the conductive through vias on the carrierfurther comprises: after removing the patterned resist layer, removing aportion of the seed layer exposed by the metal patterns.
 15. The methodaccording to claim 12, wherein during the stripping process, thestripping solution is applied by immersion.
 16. The method according toclaim 12, wherein a ratio of an amount of the aprotic solvent to anamount of the protic solvent ranges from 1:3.5 to 3.5:1.
 17. The methodaccording to claim 12, wherein at least one of the openings is formedwith an aspect ratio more than
 3. 18. The method according to claim 12,wherein a process time of the stripping process ranges from 1 minute to180 minutes, and a process temperature of the stripping process rangesfrom 25° C. to 100° C.
 19. The method according to claim 12, wherein aswelling percentage by volume of the patterned resist layer during thestripping process is approaching 0%.
 20. The method according to claim12, wherein the alkaline compound comprises a mixture of TMAH and KOH.